Measurements of ozone concentrations were carried out in the ambient air of
agricultural areas of the Metropolitan Zone of the Valley of Mexico.
Meteorological parameters, processes of synoptic scale and the possible damage
to the agricultural crops were related to the ozone levels measured. The project
was carried out in two campaigns: the first was carried out in the agricultural
areas of the Parres, Tlahuac and San Luis, Xochimilco, in the Federal District
from August 9 to August 28 of 2002; and the second was carried out in
Huixquilucan, located at Mexico State, during June and July of 2003. The
measurements were performed by continuous analyzers, whose principle of
operation is the UV-Photometry. In the first campaign (2002), the analysis of the
data showed maximum 1-hour concentrations of ozone up to 175 ppb, 169 ppb,
and 192.7 ppb in Tlahuac, San Luis Xochimilco, and Parres, respectively. During
the second campaign (2003), the maximum average 1-hour ozone concentrations
found in Huixquilucan during June and July, were up to 172 ppb and 213 ppb,
respectively. It was demonstrated that in the study areas during 2002 and 2003,
the 1-hour concentrations of ozone reached harmful values for the agricultural
crops. In the agricultural areas of San Miguel de Topilejo, characteristic damages
attributable to ozone were identified in potato and oat cultivations.
Keywords: ozone concentrations, impact on crops, foliar damage, Mexico.